A Corner of Washington, United by the Nationals (and Blue Sharks)

WASHINGTON — Hours before the World Series officially returned to this city for the first time in 86 years, the roiling red waves rolled in.

From the Metro, on foot, from their cars and on bikes and scooters, they came in their red Nationals caps and shirts, swarming toward Nationals Park. They came in red jerseys of current stars but also of past ones, a nod to the beloved players not around long enough to play a role in this October miracle.

And among those red waves were bright blue sharks — actually people in shark costumes, which only makes sense if you know the backstory. Nationals outfielder Gerardo Parra’s walk-up song is “Baby Shark,” the catchy children’s tune that has become the Nationals’ unofficial fight song and, in turn, the city’s new theme song.

In came fans who once lived by the long-gone Griffith Stadium, where the Washington Senators used to play before they left town after the 1960 season. Now there’s a hospital on the once-hallowed grounds of that ballpark, which was torn down in 1965.

And in poured people who had attended Nationals games in 2005, when the team played at R.F.K. Stadium its first year here after moving from Montreal. R.F.K.’s rickety stands and floor would shake so violently when spectators got rowdy that it felt like earthquake tremors.

Some in the crowd would remember paying $5 per seat in 2008, the team’s first season at Nationals Park. The stadium was often so empty that spectators with upper-deck tickets simply moved to front-row seats by the field.

There would be no such upgrades at Game 3 on Friday. A flood of fans arrived at Nationals Park with a singular purpose: to watch their team take on the Houston Astros and try to bring the World Series title back to this city for the first time since 1924. The wooden scoreboard from that winning series hangs in a room inside Nationals Park, forever displaying the final score of that Game 7 – Washington 4, New York 3.

“We’ve been so torn apart lately by politics, and we need this World Series,” Chuck Hughitt, 75, who grew up cheering for the Senators, said. “It’s uniting the hell out of us in these troubled times.”

Washington can be an isolating and serious place to live sometimes, considering the steady influx of tourists, the underlying tension of politics and the residents who come and go, depending on the administration. It’s uncommon to meet a Washington native, and it takes a lot for Washingtonians to get excited about the same thing. Calling it a fun-loving city would be a stretch.

In front of the White House on Friday afternoon, two Astros fans took selfies, but that was the only hint that the World Series was in town. Several protesters shouted into bullhorns, advocating East Turkestan’s independence from China.

Even among residents, the excitement for the World Series started with a small spark before catching fire.

It began with the city’s institutions: The marquee on every city bus during the last week read, “GO NATS!” The Smithsonian posted a tweet directed at Astros fans: “Houston, YOU have a problem.”

Before a performance for children at the Kennedy Center, four musicians from the National Symphony Orchestra wore shark costumes and played “Baby Shark” in the cavernous halls. Workers at Ronald Reagan National Airport posted a cheesy “Baby Shark” dance routine on social media.

The Humane Rescue Alliance, an animal shelter, named some of its homeless dogs after the team’s stars. A cuddly black puppy named Stephen Strasburg went home with a family on Thursday, with Strasburg the pitcher paying the adoption fee.

Around town, you can buy Adam Eaton Bacon Cheese Fries or a Nats en Fuego rum drink. Bakers at Astro Doughnuts & Fried Chicken stayed up all night on Thursday to make 1,800 “Baby Shark” doughnuts, selling at $3.95 each. They sold out before Friday’s game. One of Astro’s owners, Elliot Spaisman, said he briefly considered changing the shop’s name to make sure patrons knew its allegiance.

The team has transformed the city in a way that the Washington Capitals, who won the Stanley Cup in 2018, and the Washington Mystics, who won the W.N.B.A. championship this month, never could. That’s partly due to the tangible way the baseball franchise changed Washington.

When the ballpark opened in the Navy Yard neighborhood 11 years ago, the area was struggling to move past decades of drugs and violence. It was a wasteland of car repair shops, garbage truck parking lots and asphalt factories. But the ballpark led the way for restaurants, condos and hotels, and Audi Field, home of Major League Soccer’s D.C. United, down the street.

And to that shiny new Navy Yard came the fans on Friday, a happy red horde, hoping for a victory that ultimately would not come that night, as the Astros grinded out a 4-1 win.

A bagpipe player played “Baby Shark.” A singer belted out, “When the Nats Come Marching In.” Countless fans wore some kind of shark gear, including shark hats and sharks glued to caps. Matt Kucinich, a 31-year-old settlement agent, has been wearing a full-length shark costume to games since the Nationals’ wild-card game win.

It’s all part of building a tradition. Maybe even a winning one.